Synthesis of terminal disaccharide elements corresponding to the Ogawa and Inaba antigenic determinant from Vibrio cholerae O1.

Vibrio cholerae O1 LPS terminal mono- and disaccharide elements were synthesized by reduction of the azido group in several 4-amino-4,6-dideoxy-D-mannose mono- and disaccharide derivatives, followed by coupling with 2, 4-di-O-acetyl-3-deoxy-L-glycero-tetronic acid in the presence of 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline. This compound represents a useful model in order to elucidate the size of the epitopes which define Ogawa and Inaba serotypes from Vibrio cholerae O1.

Serological reactivity to a synthetic analog of phenolic glycolipid I and early detection of leprosy in an area of low endemicity.

A total of 23,863 individuals living in an area of low endemicity for leprosy were tested by enzyme-linked immunosorbent assay with a semisynthetic analogue of the phenolic glycolipid I antigen of Mycobacterium leprae. The proportion found positive was 3.86% which was significantly higher than that in a sample of a population known to be free of leprosy. Clinical examinations as well as Mitsuda and skin smear tests were organized for those defined as seropositive. The proportion of individuals with lepromin reactions of less than 3 mm increased 18.9% per serological interval as antibodies rose though it was not statistically significant. As a result of the clinical and bacteriological examinations, 2 cases with clinical signs and heavy bacillary load were found, whereas acid-fast bacilli were demonstrated in 2 other individuals without clinical manifestations of leprosy. The usefulness of the system for control purposes is discussed.

Serodiagnosis of leprosy in patients' contacts by enzyme-linked immunosorbent assay.

Serum samples from 3336 contacts of leprosy patients were tested for antiphenolic glycolipid I antibodies by enzyme-linked immunosorbent assay with the albumin coupled synthetic disaccharide antigen. The overall positivity rate was 9.3%. No significant differences were seen between a group of household contacts of lepromatous patients and those of the other types of the disease. The proportion of ELISA positives was slightly higher in the relatives as compared to workplace contacts and neighbours but significantly different only between the two former (p less than 0.05). Among those contacts with absorbance values higher than 0.100, 5 new leprosy patients were diagnosed, 2 of them with positive skin smears. A sixth contact was detected with a very high absorbance value in whom no single skin lesion was found but whose lepromin reaction was 0 mm and the skin smear showed a bacteriological index of 3+.

Inmunocomplejos circulantes en paciente de lepra multibacilar y su relación con los anticuerpos anti-M. leprae y las inmunoglobulinas mayores

Se realizó un estudio de la respuesta inmune humoral eb pacientes de lepra multibacilar, sus convivientes e individuos sanos sin contacto conecido con lepra. Los que dividieron en tres grupos: pacientes con menos de 2 años de tratamiento, pacientes que tenían más de 2 años de tratamiento y evolución satisfactoria y pacientes con más de 2 anõs de tratamiento que presentaban episodios de eritema nudosum leprosum. Se determinaran los niveles inmunocomplejos circulantes por el método de precipitación con polietilenglicol de 6000, los niveles de anticuerpos anti-M. leprae por técnica de ELISA utilizando el antígeno semisintético análogo del glicolípido fenótipo I del M. leprae y se cuantificaron las inmunoglobulinas IgA, IgG e IgM por inmunodifusión radial. En los pacientes con reacción tipo II, los valores de los inmunocomplejos y de las inmunoglobulinas IgG e IgA fueron más altos que en el resto de los grupos. La IgM y los anticuerpos anti-M. leprae disminuyeron con el tiempo de tratamiento, tendiendo ambos a una relación inversa con los inmunocoplejos.

[Monitoring of the treatment effectiveness in patients with leprosy using solid-phase immunoenzyme assay]. / Monitoreo de la eficacia del tratamiento en pacientes con lepra mediante el ensayo inmunoenzimático sobre fase sólida.

Serum samples from 184 lepers are studied by means of solid phase ELISA with the semisynthetic antigen disaccharide-bovine albumin analogous of phenolic glycolipid I of Mycobacterium leprae. Patients are grouped according to the clinical presentation of the disease and course of time elapsed since the institution of therapy. Bacilloscopic examinations were made also in 116 patients who were positive at diagnosis. For serologic testing, absorbance values over 0,160 were considered positive. Results in multibacillary patients showed a gradual and significant decrease both of mean absorbance values and in the seropositive ratio in connection with the length of treatment. It was also found that phenolic anti glycolipid antibodies increased with the value of the bacteriologic index. This system is useful in monitoring the effectiveness of chemotherapy in multibacillary leprosy.

Inmunofluorescencia indirecta para la deteccion de anticuerpos anti-M. leprae. Aplicacion a un grupo de pacientes y convivientes. / Indirect immunofluorescence for detecting anti-M leprae antibodies. Its use in a group of patients and people living together with them

Se realizo un estudio de la tecnica de inmunofluorescencia indirecta, para detectar anticeurpos anti-M. leprae, descrita por el doctor M. Abe, con el objetivo de evaluar su utilidad en nuestro medio. Los resultados obtenidos fueron comparables a los del trabajo de Abe coloboradores, lo que demuestra la repetibilidad del metodo, asi como la utilidad del mismo para estudios seroepidemiologicos